Automotive electrical cables are rigidly bolted to the battery terminals, making it literally impossible to remove them instantly, which removal is of utmost importance when an emergency arises such as an electrical short circuit, a fire, or even a stuck accessory like a horn. Also, the capability to cut off battery power quickly is of great convenience when performing certain repairs.
Electrical short circuits are a major cause of vehicle fires. Contrary to common belief, some circuits are not protected with fuses. For example, full battery power is usually carried by heavy gage wires through the firewall to the ignition switch and relay and to the voltage regulator continuously and without fuse protection, even when all accessories and switches are turned off. Power is cut to these locations only when a cable is removed from either battery terminal or when a circuit breaker like the present invention is activated. A short circuit or malfunction of the relay, regulator, or ignition switch is a major cause of electrical fires and total destruction of the vehicle electrical wiring. Even if the driver has proper tools, he could not remove the battery cable in time to prevent extensive wiring destruction and/or fire.
The battery disconnect must be instantaneous when a short occurs, and the present invention makes this possible. It permits instant power disconnect and reconnect with the movement of the ignition switch. Most drivers will want to open the circuit whenever the vehicle is unattended. Also, since the engine cannot be started without battery power, theft will be thwarted. Further, quick disconnect of battery power is a great convenience when certain mechanical repairs are being performed.
The primary purpose of the present invention is to provide a quick, reliable, and convenient master circuit breaker which is equivalent to removing a cable from one of the battery terminals.
Prior to this invention, conventional circuit breakers for motor vehicle battery power isolation from one master switch have not been feasible because the high amperage requirement of the starter motor would activate any conventional circuit breaker designed to protect the small amperage wiring of the accessory circuit.
The invention includes three circuit breaker designs: (1) the solenoid operated open and close system, (2) the solenoid operated open and close system having a backup provision manual actuation and (3) the manually operated system.